having poles set alternately all round a circular frame. Figs. 4 and 5 show how this is carried out. A cast-iron ring having projecting iron pieces screwed into it is surrounded by zig-zag conductors which carry into it the current from a separate exciter. These currents pass up and down between the projecting cheeks, and excite those on both sides of them.

A still more recent, and still larger generator, is that designed by Mr. J. E. H. Gordon, whose "Physical Treatise on Electricity and Magnetism" is known to most of our readers. This machine, which is given in elevation in Fig. 6, and in end-elevation in Fig. 7, is more than 9 feet in height, and weighs 18 tons. It possesses several points of interest. The rotating armature differs from those of the well-known Gramme or Siemens' armatures, being in form a disc, constructed of boiler-plate, upon which the coils are carried. The machine, therefore, resembles in some respects the Siemens' alternate-current machine, though there are notable points of difference, the most important

from 5000 to 7000 if the driving power is proportionately increased. The machine is now in operation at the Telegraph Construction and Maintenance Company's Works, East Greenwich.

A great deal has been said in certain quarters of late about another new dynamo, the invention of Mr. Ferranti, which, with one of those unscientific exaggerations which cannot be too strongly condemned, was pronounced to have an efficiency five times as great as that of existing dynamos. The construction of this machine has not yet been made known, but it is understood that it has no iron in the rotating armature. This is, however, no novelty in dynamos. It appears, also, that Mr. Ferranti has invented an alternate-current machine almost identical with that of Sir William Thomson described above.

Lastly, M. Gravier claims to have designed a form of dynamo in which there are neither commutators nor separate exciters, but in which continuous currents of electricity are produced in stationary coils by the passage near them of a rotating series of iron bars whose mag

E

FIG. 7.-End Elevation and Section of Gordon's Dynamo. being, that whereas in most dynamo-machines the inducing field-magnets are fixed, and the induced coils rotating, in Mr. Gordon's new machine the rotating coils are those which act inductively upon the fixed coils between which they revolve. The machine furnishes alternate currents, and therefore requires separate exciters. These exciters, two Bürgin machines, send currents which enter and leave the revolving armature by brushes pressing upon rings of phosphor bronze placed upon the axis at either side. There are 64 coils upon the rotating disc, and double that number upon the fixed framework. These 128 "taking-off" coils, the form of which is shown in Fig. 8, are alternately connected to two circuits, there being 32 groups in parallel arc, each parallel containing 4 coils in series; thus bringing the total electromotive force to 105 volts when the machine is driven at 140 revolutions per minute. At this speed it actuates 1300 Swan lamps, but is calculated to actuate

FIG. 8.-The Fixed Coils of Gordon's Dynamo.

netism is changed, during their passage, by the reaction of the cores of the stationary coils themselves. M. Gravier has also designed a machine in which a Gramme-ring is wound with two sets of coils, a primary and a secondary, each set having its own commutator on opposite ends of the axis. A current from a separate exciting machine passes into the primary coils of the ring by one pair of brushes, and the secondary current is taken off by a second pair of brushes at the other commutator placed at right angles to the first pair. We are not aware that any practical machine thus constructed has yet been shown

in action.

It is certain that there is yet abundant room for great improvement in the construction of dynamo electric machines. But the inducements to improvement at the present time are so great that rapid progress toward the is more than assured.

desired goal of perfect efficiency and simplicity of structure

THE PROJECTION PRAXINOSCOPE

M. GASTON TISSANDIER describes in La Nature

an ingenious adaptation of the praxinoscope, under the above name, by means of which the images are projected on a screen, and are visible to a large assembly.

NOTES

WE take the following from the Times:-The council of the Royal Society have awarded the medals in their gift for the present year as follows: The Copley Medal to Prof. Cayley, F.R.S., for his researches in pure mathematics; the Rumford Medal to Capt. Abney, F.R.S., for his photographic researches and his discovery of the method of photographing the less refrangible part of the spectrum, especially the infra-red region; a royal medal to Prof. W. H. Flower, F. R.S., for his contributions to the morphology and classification of the mammalia and to anthropology; and a royal medal to Lord Rayleigh, F. R.S., for his papers in mathematical and experimental physics; the Davy Medal (in duplicate) to D. Mendelejeff and Lothar Meyer for their discovery of the periodic relations of the atomic weights. These medals will be presented at the anniversary meeting of the society on St. Andrew's Day.

middle of the background, where it then appears to gambol. A hand-lever on the foot of the instrument allows a moderate and regular rotation to be communicated. This apparatus, with an ordinary moderator lamp, supplies well-lighted pictures and curious effects. It enables us to obtain, with the greatest ease, animated projections, without requiring any special source of light, by simply utilising the lamp in daily use.

THE President and Council of the Geological Society hold a conversazione in the Society's rooms on Wednesday, the 29th inst. Fellows of the Society who have objects of interest suitable for exhibition are asked kindly to lend them for the occasion.

IT is announced that General Pitt Rivers will be appointed Inspector of Ancient Monuments under the recent Act. WE announced last week the death, at the age of sixty. six years, of Prof. Johannes Theodor Reinhardt, Inspector of the Zoological Museum of the University of Copenhagen. Prof. Reinhardt was a well-known zoologist, author of an excellent memoir on the Birds of the Campos of Brazil, and of numerous papers in the scientific periodicals of Copenhagen, and will be regretted by many friends and correspondents in this country.

AT the sitting of the Paris Academy of Sciences on November 13, M. Faye read letters from the captain of the Niger, French

war steamer, on the comet, stating that it was seen at Buenos Ayres, in the streets, on November 18, in close vicinity to the un, and that the tail was seen for the first time on board the Niger on September 26. The expanse of the tail was then 28°, and its transversal dimension 26°. The quantity of light was so great that when the end of the tail began to become visible the officers and sailors witnessing the phenomenon were quite unable to understand the real nature of this splendid illumination.

MR. B. J. HOPKINS, of Dalston, sends us a drawing of the head of the comet, which he saw on November 8, 16h. 50m. Viewed with the naked eye, Mr. Hopkins states, the nucleus appeared equal to a second-magnitude star; the tail was distinctly visible, having a length of about 19°; it was straight for four-fifths its length; it then abruptly curved upwards and spread itself out in the shape of a fan, with a breadth of 4°. It was still brightest on the southern side. Observing at 17h. 30m. the nucleus-as seen with a 5-inch refractor-had the appearance of being double, there being two portions of equal brightness separated by a narrow space of less brightness, the whole being surrounded by a circular nebulosity. The line joining the two bright portions of the nucleus formed an angle with the axis of the tail; and the tail immediately following the nucleus was most clearly and sharply divided into two portions of unequal brightness, the southern, as before mentioned, being by far the most brilliant. The dark rift in the tail was not so conspicuous

as on the 5th inst.

M. TRESCA presented to the Academy of Sciences on Monday the third part of his great work on measures taken during the Paris Electrical Exhibition. It relates to the analysis of electric candles, and will be followed by a similar work on incandescent lights. M. Mascart sent a paper on measures taken with the registering electrometer in compliance with the wish expressed by Sir William Thomson to test the relations of the state of the weather and the electrical properties of the

air.

AT the same meeting M. Janssen read in the name of the Bureau des Longitudes a report on the observations which will be made during the total eclipse of the sun of May 6, 1883, which will be observed in the Pacific Ocean. He also read a paper on his work on solar spectroscopy, and on the observation of telluric rays. Admiral Mouchez read a letter from M. Henry, who has been sent to the Pic-du-Midi to observe the forthcoming transit of Venus and determine the possibility of establishing an astronomical observatory on the top of the mountain.

THE French Journal Officiel has published a decree of the President establishing a council for the Observatory of Mentone.

WE are informed that the contract for the construction and erection of the Forth Bridge has been let to Sir Thomas Tancred, Bart., Mr. J. H. Falkiner, and Mr. Joseph Phillips, Civil Engineers and Contractors, of Westminster, and Messrs. Arrol and Co. of the Dalmarnock Iron Works, Glasgow. Messrs. Tancred and Falkiner have already carried out about seventy miles of railway for Mr. Fowler, and are at present constructing the new line to Southampton. Mr. Phillips has had a very wide practical experience in bridge construction and erection, and Messrs. Arrol and Co. are contractors for the new Tay Bridge, so the works are in good hands. The contract sum is 1,600,000!., which is within 5000l. of the engineer's parliamentary estimate. The tenders received ranged from 1,485,000l. to 2,300,000l., most of the leading firms being represented.

AT the annual general meeting of the Cambridge Philosophical Society, a resolution recording the deep regret of the Society at the lamentable event which deprived them of their late president,

Prof. F. M. Balfour, was carried unanimously, and a letter expre-sive of their feelings was directed to be sent to Mrs. Henry Sidgwick (Prof. Balfour's sister). The officers for the ensuing year were appointed as follows:-President, Mr. J. W. L. Glaisher, F.R.S.; Vice-Presidents: Profs. Babington, Newton, and Cayley; Treasurer, Dr. Pearson; Secretaries: Mr. J. W. Clark, Mr. Trotter, and Mr. W. M. Hicks; new Members of Council: Dr. Campion, Mr. E. Hill, and Mr. J. N. Langley.

WITH regard to the recent sad suicide of a girl by leaping from one of the towers of Nôtre Dame, Dr. Bronardeli's expre-sed view that asphyxiation in the rapid fall may have been the cause of death, has given rise to some correspondence in La Nature. M. Bontemps points out that the depth of fall having been about 66 metres, the velocity acquired in the time (less than four seconds) cannot have been so great as that sometimes attained on railways, e.g. 33 metres per second on the line between Chalons and Paris, where the effect should be the same; yet we never hear of asphyxiation of engine drivers and stokers. exploded, as unhappy persons may be led to choose suicide by He considers it desirable that the idea in question should be

fall from a height, under the notion that they will die before reaching the ground. Again, M. Gossin mentions that a few years ago a man threw himself from the top of the Column of July, and fell on an awning which sheltered workmen at the pedestal; he suffered only a few slight contusions. M. Remy says he has often seen an Englishman leap from a height of 31 metres (say 103 feet) into a deep river; and he was shown in 1852, in the island of Oahu, by missionaries, a native who had fallen from a verified height of more than 300 metres (say 1000 feet) His fall was broken near the end by a growth of ferns and other plants, and he had only a few wounds. Asked as to his sensations in falling, he said he only felt dazzled.

DR. SLUNIN has published in Russian a work—“Materials for the Knowledge of Popular Medicine in Russia "—which will be received with interest, not only by medical men but also by ethnographers. Dr. Slunin gives a detailed account of all plants and drugs used not only in Russian popular medicine in the governments of Saratoff and Astrakhan, which he knows from many years' residence, but also in all Persian, Tartar, and Central Asian medicines (with their Arabian names) that have come to his knowledge. His remarks on popular pharmacies and on the popular medical literature which goes as far back as the epoch of the flourishing times of Arabian civilisation are of great interest.

THE Catalogue of the Reference Department of the Derby Free Library is of a handy size and excellent type. We are told it contains 60,000 references to works upon the library shelves; and, upon dipping into it, the minuteness of connection which will lead to a reference to publications of scarcely higher standing than a newspaper, is imposing. We grieve to add, however, that this holds good in both senses of the word. For looking more closely we find most important references are absent. As

a sample, eight references are given to the name of Garrick, but neither is his life by Murphy or Davies quoted, nor is any reference made to Boswell's "Johnson," or Goldsmith's Poems; and the extraordinary explanation of this is found in the fact that neither of these works is in the library! And this absence of important works seems to be the rule rather than the exception, jects. Looking through the letter B as a sample, we find no carried out also with the most even-handed fairness to all subworks of Babbage, Back, Barbauld, Barry (Sir C.), Baxter, Beale, Baden Powell, Brewster, Barrow (Isaac or Sir Jno.), Bayne, Beckmann, Blackie, Blackstone, Borrow, Boswell, Bowring, Bridgewater Treatises, Browning (Mrs.), Buckmaster, Buxton, Butler (Bp.), or Butler (S.). Among Dictionaries neither the Penny nor the English Cyclopædia is to be found.

Nor is it that a selection of certain writers has been made, for numerous authors of many well-known works are only credited with one or two in the Derby Library Catalogue. The letter B is not a specially unfortunate one. Ancient Geography refers only to Nature and the Quarterly Review (one reference each). Gladstone and Hugh Miller are equally unknown. Less than a column contains all the references to Geography, while Geology has nine columns allotted to it. Under Astronomy the inquirer is referred to numerous papers where notices may be found of each of the planets and of many of the planetoids, but only fifteen works on Astronomy are catalogued. There is no work at all upon the Moon! Moreover, the references to works which are in this library are made with no discretion. "Barbarossa" does not refer the reader to Gibbon; "Borgia" only refers him to one article-on Lucrezia — in the Nineteenth Century! The spelling is not only unscholarly, but the correcting of proofs is careless. It were endless to point out the blunders everywhere; we need only refer to the name of Prof. Haeckel, spelt in four different ways upon pp. 41, 42 only! If some little town struggling against the smallness of the Id. rate wishes to draw as much as possible from its Free Library with its motley collection of books contributed from various quarters, we can strongly recommend the system upon which this catalogue is drawn up. But that a place of the size and importance of Derby, whose rate also has been so helped by the munificence of Mr. Bass and others, should think it worth while to print and distribute a catalogue, displaying a knowledge and a collection of books in this rudimentary state, is beyond our comprehension.

THE population of Cascia (Italy) is being constantly disturbed by repeated subterranean shocks.

A VOLCANIC eruption is reported to have taken place from a mountain in the Caucasus, which has not shown any volcanic phenomena during historic times. It is the Karabetow mountain, Lear Temrink, in the government of Jekaterinodar (Caucasia). The subterranean noi e was heard 4 versts away, the lava flowed for a distance of half a verst, and a large crater was formed.

NEWS from Belgrade states that some railway workmen have discovered a nearly perfect mammoth skeleton. It is being photographed on the spot, and will be handed over to the National Museum at Belgrade.

A NATURAL intermittent spring has recently formed in the Jachère (Hameau de l'Argentière, Hautes Alpes). At regular intervals of five and seven minutes it yields 10 litres of water each time. It is very remarkable that the first time it consists of lukewarm and colourless water, but the second of cold but wine-red water. MM. Chester and Hadley are now studying the phenomenon.

M. J. OLLER, the proprietor of the St. Germain racing establishment, is preparing to organise night races. He intends to build a central lighthouse, of which the rays will be directed on the contending horses, so that spectators sitting in the centre may follow the proceedings with as much accuracy as in open day.

AT the annual meeting for the distribution of prizes in Mason College, Birmingham, Prof. Tilden gave a sensible and interesting address on Technical Education, which has been published in a separate form.

THE Captaia-General of the Philippines reports another destructive hurricane on November 5, and it is worthy of remark that since the previous hurricane, a few weeks ago, the cholera, which had been very bad, has nearly disappeared from Manila.

MESSRS. SONNENSCHEIN AND CO. announce the forthcoming publication of Dr. Coppinger's Notes of the four years' voyage from which the Alert has recently returned.

MR. MURRAY has issued a cheap edition of Dr. Blaikie's "Life of David Livingstone."

THE additions to the Zoological Society's Gardens during the past week include two Macaque Monkeys (Macacus cynomolgus 88) from India, presented respectively by Mr. J. Knight and Mrs. Snell; a Sooty Mangabey (Cercocebus fuliginosus 8) from West Africa, presented by Lady Stafford; two Globose Curassows (Crax globicera ¿?) from British Honduras, presented by Mr. R. W. Ryass; a Buzzard ( ) from Demerara, presented by Mr. G. H. Hawtayne, C.M.Z.S.; three Common Chameleons (Chameleon vulgaris) from Egypt, presented by Mr. W. J. Ford; a Hawk's-billed Turtle (Chelone imbricata) from West Indies, presented by Mr. W. Cross; a Pig-tailed Monkey (Macacus nemestrinus 8) from Java, a Black Wallaby (Haimaturus ualabatus ?) from New South Wales, a Greek Land Tortoise (Testudo graca), South European, deposited; an American Bison (Bison americanus) from North America, a Capybara (Hydrocharus capybara ?) from South America, two Eastern Goldfinches (Carduelis orientalis) from Afghanistan, two Brent Geese (Bernicla brenta), a Red-throated Diver (Colymbus septentrionalis), British, purchased; three Capybaras (Hydrocharus capybara ¿ ¿?), a Bluish Finch (Spermophile cærulescens) from South America, received in exchange.

GEOGRAPHICAL NOTES

Ar the opening meeting of the Geographical Society on Monday Mr. A. R. Colquhoun gave an account of his recent adventurous journey, in company with the late Mr. Wahab, from Canton through Yunnan to Bhamo. Mr. Colquhoun's object was mainly to discover trade-routes between Burmah and China, but he collected some interesting information on Further Yunnan, parts of which have not before been visited by European travellers. Mr. Colquhoun describes Yünnan, which is the most westerly of the eighteen provinces of China, as a great uneven plateau, of which the main ranges trend north and south; those in the north reaching an elevation of from twelve to seventeen thousand feet, while in the south they sink to seven or eight thousand feet. In the south, and especially in the south-west, there are many wide fertile plains and valleys, some with large lakes in them. These plains are very rich and thickly populated, the number of towns and villages and the comfortable appearance of the peasantry being very remarkable. Fruits of all kinds-pears, peaches, chestnuts, and even grapes-are found in abundance, while roses, rhododendrons, and camelias Minerals of several varieties grow untended on the hill-sides. are found in great quantities. The travellers constantly passed caravans laden with silver, lead, copper, and tin in ingots; and gold is beaten out into leaf in Tali, and sent in large quantities to Burma. Coal, iron, silver, tin, and copper mines were frequently passed. Mr. Colquhoun alsɔ found that the celebrated Puerh tea, the most fancied in China, is not really a Chinese tea at all, but is grown in the Shan district of I-bang, some five days south of Puerh, the nearest prefectural town. In the south the tempera

ture is moderate, and the rains by no means excessive; but the farther north the travellers went, the more sparse became the population, and the more sterile the country, until in the extreme north the hills were enveloped in al nost perpetual fogs, rain, and mists, and were practically uninhabitable. The people themselves are mostly the old aboriginal tribes-Lolo, Pai, and Maio-the Chinese being mostly of the official class, and found only in the towns. These aborigines have a much more distinct physiognomy than the bullet-headed Celestial, and are remark able for their frank and genial hospitality. The women do not crush their feet, and they adopt a picturesque dress not unlike that worn of old by Tyrolese and Swiss maidens. They have a novel way of making marriage engagements. On New Year's Day the unmarried people range themselves, according to sex, on either side of a narrow gully. The ladies in turn toss a coloured ball to the other side, and whoever catches it is the

happy man. It is said they are so skilful in throwing the ball that the favoured man is always sure to catch it; which is reassuring. As in Marco Polo's days, the couvade still prevails in

some parts. When a child is born, the husband goes to bed for thirty days, and the wife looks after the work. At the conclusion of the paper, Lord Northbrook and Col. Yule paid a well deserved tribute to the late Capt. Gill, Prof. Palmer, and Lieut. Charrington. Capt. Gill, our readers may remember, had himself done some first-rate work on the South-East Chinese frontier, and described it in his "River of Golden Sand; while Prof. Palmer's loss as an Arabic scholar is almost irretrievable.

SAMOYEDES report to Archangel that they have recently seen, south of Waigatz Island, the wreck of a large vessel crushed in the ice. If the statement be true, and if we remember their never-credited story of the unfortunate Jeannette, it is more than probable that the vessel is either the Danish exploring vessel the Dijmphna, with Lieut. Hovgaard's expedition, or the Norwegian steamer Warna with the Dutch meteorological expedition, bound for Port Dickson, both of which in September last froze in in the Kara Sea, from which place the ice may subsequently have carried the unfortunate vessel to where she now is stated to be. The last intelligence received from Lieut. Hovgaard was dated September 22, and addressed to Herr Aug. Gamil, of Copenhagen, the principal promoter of the expedition, from which it appears that all was then well with both vessels, but that the Dijmphna was, when caught in the ice, some considerable distance from shore, in fact in a spot where the whole force of the polar ice, when in drift, would strike her. Herr Aug. Gamil having telegraphed to the Russian Admiralty for any confirmation of the above report, has received a reply that no official information on the subject has been received at St. Petersburg; but that nevertheless instructions would be at once given to the officials on the north coast to scour the same, and gather further particulars. A search party is also being contemplated in Copenhagen, which will, if decided on, be led by M. Larsen, a Dane, who accompanied the American expedition in search of the crew of the Jeannette, as the special artist of the Illustrated London News.

THE German Government has raised the fund for the scientific exploration of Central Africa and other countries, which in 1882-83 was fixed at 75,000 marks (37507.) to 100,000 marks (5000/.) for the financial year 1883-84.

THE AIMS AND METHOD OF GEOLOGICAL
INQUIRY1
II.

IT will be observed that the results obtained by geologists

could not have been arrived at had they confined themselves solely to the detection of resemblances and correspondences between the phenomena of the present and the past. The natural forces have always been the same in kind, if not in degree, and we can often watch the gradual development by their means of products which more or less closely resemble the rocks of our sections. But experimental evidence of this kind takes us only a short way, and we are sooner or later confronted by appearances, which are not reproduced by nature before our eyes.

As another example of this I shall adduce one which, although it has far-reaching issues, has yet the merit of being readily comprehended without much prelim nary geological knowledge. It is moreover instructive as showing how the imaginative faculty works in a mind trained to clear and steady observation of nature. The fact that a large proportion of the lakes of the world rest in rocky hollows or basins had been long known before it occurred to any one to ask how such rocky hollows had come into existence. The question was first asked and the answer given by Prof. (now Sir) A. C. Ramsay. He had pondered over the problem for years before its solution dawned upon him. None of the ordinary agents of geological change seemed capable of producing the phenomena. most common of all denuding agents-water-certainly could not do so, for although it may dig long and deep trenches through rocks, water could not scoop out a basin like that occupied by Loch Lomond, or any of our Highland lakes. tendency of water is, on the contrary, to silt up and to drain such hollows, by deepening the points of exit at their lower ends. Did the hollows in question occupy areas of depression-had

The

The

The Inaugural Lecture at the opening of the Class of Geology and Mineralogy in the University of Edinburgh, October 27, 1882, by James Geikie, LL.D., F.R.S. L. and E., Regius Professor of Geology and Mineralogy in the University. Continued from p. 46.

they, in short, been formed by unequal subsidences of the ground? Some considerable inland seas, as for example the Dead Sea, and doubtless many larger and smaller sheets of water, owe their origin to local movements of this kind. But it is incredible that all the numerous lakes and lakelets of Northern Alpine regions could have originated in this way. In many cases these lakes are so abundant that it is hard to say of some countries, such as Finland, and large parts of Sweden, and even of our own islands, whether it is land or water that predominates. If all these numerous and closely aggregated rock-basins represent so many local subsidences, then the hard rocks in which most of them appear must have been at the time of their formation in a condition hardly less yielding than dough or putty. It was suggested that the lakes of the Alps and other hilly regions might have been caused, not by local sinkings confined to the valleys themselves, but by a general depression of the central high-grounds and water-sheds. The subsidence of the central mountains would of course entail depression in the upper reaches of the mountain-valleys, and in this way the inclination of those valleys would be reversed-each being converted into an elongated rock-basin. But a little consideration showed that before the lakes of such a region as the Alps could have been produced in this manner, those mountains must have been some 15,000 feet higher than at present. Or to put it the other way, in order to obliterate the Alpine lakes and restore the slopes of the valleys to what, if this hypothesis were true, must have been their original inclination, the Alps would need to be pushed up until they attained twice their present elevation. Now, we are hardly prepared to admit that the Swiss mountains were 30,000 feet high before the glacial period. If our Alpine and Northern lake-basins cannot be attributed to movements of depression, still less can they be accounted for by any system of fractures ; -they lie neither in gaping cracks nor on the down-throw sides of dislocations. In a word, a study of the structure, inclination, and distribution of the rock-masses in which our lake-basins appear throws no light upon the origin of those hollows. We probably find in many cases that the position and form of a basin have been influenced in some way by the character of the rocks in which it lies-but we detect no evidence in the rock-masses themselves to account for its production. It is not necessary, however, that I should on this occasion mention each and every cause which has been suggested for the origin of rock-bound hollows. Some of these suggestions are unquestionably well founded. For example, there can be no doubt that certain lakes have been produced by the sudden damming-up of a valley in consequence of a fall of rock from adjoining slopes or cliffs; others, again, occupy holes caused by the falling in of the roofs of caves and subterranean tunnels; while yet others have been formed by a current of lava flowing across a valley and thus ponding back its stream, just as many a temporary sheet of water has been brought into existence in a similar way by the abnormal advance of a glacier. In these and other ways lakes have doubtless originated again and again, but the causes ju-t referred to are all more or less exceptional, and manifestly incapable of producing the phenomena so conspicuous in the lakeregions of Britain, Scandinavia, and the Alps.

Ramsay, to whom the varied phenomena of glacier-regions had been long familiar, was struck by the remarkable fact that freshwater lakes predominate in Northern and Alpine countries, while they are comparatively rare in regions further south and lakes in Finland finds no counterpart in the low grounds of outside of mountainous districts. The great development of

southern latitudes. It is in regions where glacial action formerly prevailed that rock-basins are most numerous, and this suggested to Ramsay that in some way or other the lakes of the Alps and the North were connected with glaciation. The final solution of the problem flashed upon him while he was studying the glacial features of Switzerland. His scientific imagination enabled him to reproduce in his own mind the aspect presented by the Alps during the glacial period, when the great mountain-valleys were choked with glacier-ice, which flowed out upon the low grounds of Germany, France, and Northern Italy, so as to cover all the sites of the present lakes. He saw that under such conditions enormous erosion must have been effected by the ice, by means of the rocky rubbish which it dragged on underneath, and that this erosion, other things being equal, would be most intense where the ice was thickest and the ground over which it advanced had the gentlest inclination. Such conditions, he inferred, would be met with somewhere in the lower course of a valley between the steeper descent of its upper reaches and the